This invention relates to film holding apparatus and more particularly to cassettes for holding radiographic film.
There has been developed a film cassette for x-ray or other radiographic film which is of unique, light-tight construction and is extremely simple to use. Representative cassettes of this type are disclosed in Harry S. Wolf U.S. Pat. No. 2,213,437 granted Sept. 3, 1940. Such cassettes customarily include a front panel and a back panel having a felt cushion. The film is positioned between intensifying screens located intermediate the two panels. The cassettes commonly are stored within the screens and film in place on shelves in radiographic rooms or other locations with only the edges of the cassettes visible. When a picture is to be taken, an orderly or technician selects the cassette with the appropriate screen and film combination, and the picture is made.
Heretofore, difficulties have been encountered in the construction and handling of film cassettes and similar film holding apparatus. Of particular importance is the need for rapidly and accurately identifying a given cassette and distinguishing it from the comparatively large number of adjacent cassettes at the storage location. In the making of an x-ray picture, for example, one of the more significant parameters is the speed of the screens within the cassette, and it is important to determine the screen speed quickly and without excessive handling. Also, information often is needed concerning the particular department or radiographic room in which the cassette has been stored, the type of cassette, e.g. photo-timing, grid cassette, etc., or other factors necessary or desirable to determine selected parameters consistent with the purpose for which the cassette is employed. Prior cassettes have proved deficient in these respects, with the result that in several instances the cassettes have been incorrectly identified and a substantial amount of time was wasted before the proper cassette could be located.